Warp beam letoff

ABSTRACT

Apparatus to let the tension off of a loom warp beam as the warp yarn on the beam is being consumed by the loom.

I United States Patent 1151 3,640,31 5 Tisdale Feb. 8, 1972 [54] WARP BEAM LETOFF 2,670,764 3/1954 Randall et al ..I39/107 2,914,092 11/1959 Clentimack ..139/l08 Game)" 3,100,511 8/1963 Grob ..139/107 [73] Assignee: Deering Milliken Research Corporation,

Spartanburg, S.C. FOREIGN PATENTS OR APPLICATIONS [22] Filed: Dec. 22, 1969 708,289 5/1954 Great Britain ..l39/l07 [21] Appl' 887464 Primary Examiner-James Kee Chi Attorney-Norman C. Armitage and H. William Petry [52] US. Cl ..l39/l07 [51] Int. Cl. ..D03d 49/06 57] ABSTRACT [58] Field ofSearch ..l39/108,107, 109,100, 310,

139/1) Apparatus to let the tens1on off of a loom warp beam as the warp yarn on the beam is being consumed by the loom. [56] References Cited 1 Claims 3 Dm Figures UNITED STATES PATENTS 8/1949 Williams "1139/10? mmm m 3640.315

Flaw v.-

20 m E /2 1/6 E g 54 Hg? 8 72 g l 150 70 E 64 i 68 24 38 Z: 28

INVENTOR. ALFONSO TISDALE ATTORNEY WARP BEAM LE'IOFF The warp beam of a loom is driven by the takeup of yarn by the loom. When the warp beam is full the mass of the yarn on the beam provides a moment of inertia that is greater than when the beam is empty. Therefore, it is necessary to provide a means to restrict the beam from overriding as the beam is rotated. At the same time, it is necessary to readjust the restriction means as the yarn on the beam is woven to lessen the tension on the beam since the moment of the beam reduces as the yarn is being consumed.

Therefore it is an object of the invention to provide a tension control which will automatically let off the tension on the warp beam as the yarn on the beam is being used.

Other objects and advantages of the invention will become readily apparent as the specification proceeds to describe the invention with reference to the accompanying drawings, in which:

FIG. 1 is a side view of the warp beam end of a loom;

FIG. 2 is a front view of that portion of the loom shown in FIG. I; and

FIG. 3 is a blown-up perspective view of mechanism to provide tension on the warp beam.

As is well known in the art, the shaft of the warp beam 12 with warp yarn thereon is supported in suitable bearings 14 connected to the frame 16 of the loom. Connected to the warp beam flange 18 is a beam gear 20 which drives the gear 22 fixed on the shaft 24 which is supported by the bearing 26 in the frame and rotates the friction wheel 28 in a direction opposite to the rotation of the warp beam 12.

To maintain tension on the warp yarn and to restrict rotation of the warp beam 12, a brake strap 30 encircles the friction wheel 28 and is locked into position by the latch 32 affixed thereto atone end thereof. At the other end of the brake strap is a U-shaped plate member 34 attached thereto by suitable rivets 36 and secured in position by engagement with a slotted pin member 38 which is welded or otherwise secured to the bracket 40 attached to the loom frame by a screw member 42. One leg 44 of the U-shaped bracket 34 slides into the slot 46 and prevents the strap 30 from moving.

A rotatable shaft member 48 is secured in the frame 16 to interconnect the beam arm 50 and the lever 53. Beam arm 50 is rigidly secured to the shaft 48 by setscrew 52 at one end and has a beam lever roll 54 at the other end that rides on the warp yarn on the beam 12. A torsion spring 56 is secured between the frame 16 and a locknut 58 to bias the shaft 48 and the beam arm 50 away from the beam I2 to move the beam arm 50 automatically away from the beam when the strap 30 is loosened to relieve tension on the beam.

At the other end of the shaft member 48 is secured the lever 53 to which a collar 55 is secured and into which the end of the rod 60 is screwed. The rod 60 projects upwardly and bends at 62, projects through and beyond the opening 64 in the bracket 66 and is supported in the notch 68 in the U-shaped plate member 34. The rod 60 is threaded at the upper am and projects through a spring 70 held between the wingnut 72 threaded on the end of the rod 70 and flat projection 74 on bracket 66. The bracket 66 has a curved portion 76 over which buckle 78 is telescoped to place tension on the strap 30. It should be noted that the lever 53 has a plurality of openings therein to allow the rod 60 to be placed in different positions to vary the tension applied by the strap 30.

In operation, the buckle 78 is telescoped over the curved portion 76 and the latch 32 is pivoted to the position shown in FIG. 1 to tighten the strap 30 around the friction wheel 28. The wingnut 72 is then tightened against the spring 70 to slide the bracket 66 to the correct position to pull on the buckle 76. Then the locknut 58 is adjusted to adjust the torsion of spring 56 to place the proper amount of force on the beam arm 50. It can be seen that as the diameter of the beam decreases, the beam arm 54 will pivot counterclockwise causing the lever arm 53 to rotate in the same direction. As the lever 53 rotates in the counterclockwise direction, the rod 60 will be pushed upwardly against the bias of spr in :70, thereby releasing some 0 the force on the strap 30 who in turn relieves the restrictive force on the rotation of the warp beam 12.

Thus it can be seen that apparatus is provided that will automatically relieve the restrictive tension on a warp beam as the diameter of the beam decreases due to the usage of the warp yarn by the loom. The herein disclosed apparatus is reliable, relatively inexpensive and uncomplicated.

Although I have described in detail the preferred embodi ment of my invention, I contemplate that many changes may be made without departing from the scope or spirit of the invention and I desire to be limited only by the claims.

That which is claimed is:

l. A letoff mechanism for a loom warp beam comprising: a frame, means supporting a warp beam in said frame, means to apply a force opposing the rotation of said warp beam, a shaft member supported in said frame with both ends projecting outwardly from said frame, an elongated rod member connected to one end of said shaft member and bearing against said warp beam, a lever member connected to the other end of said shaft member, rod means connected to lever member and to said force-applying means to reduce the force applied to said warp beam by said force-applying means as the diameter of said warp beam is reduced and a spring means operably associated with said shaft member to bias said elongated rod member in a direction away from the warp beam. 

1. A letoff mechanism for a loom warp beam comprising: a frame, means supporting a warp beam in said frame, means to apply a force opposing the rotation of said warp beam, a shaft member supported in said frame with both ends projecting outwardly from said frame, an elongated rod member connected to one end of said shaft member and bearing against said warp beam, a lever member connected to the other end of said shaft member, rod means connected to lever member and to said force-applying means to reduce the force applied to said warp beam by said force-applying means as the diameter of said warp beam is reduced and a spring means operably associated with said shaft member to bias said elongated rod member in a direction away from the warp beam. 